To allow manipulation of the fuel assemblies in a nuclear reactor, the assemblies are usually provided with a lifting handle or the like. The fuel rods in the assemblies are surrounded by a fuel channel. A top support may be provided in conjunction with the fuel channel at the lifting side, in order to maintain constant spacing between adjacent fuel assemblies. Alternatively the top support may be arranged to retain and position the fuel channel in relation to the lifting part. U.S. Pat. No. 4,707,328, describes and illustrates the design and arrangement of a top support, passing through the fuel channel and being secured to the fuel channel and to the lifting handle. Through-holes for screws are provided in the angle-piece ends of the top support. When the top support is in place it is screwed to the handle by a screw passing through said holes. Alternatively a loose locking pin with bajonet catch may be used, fitted into a groove electro-erosion machined in the handle.